This invention relates to product cushioning devices for use in packaging shock sensitive products. In particular, the invention relates to re-usable or recyclable product cushioning devices which are made from plastics material, and which may have several different embodiments including corner pieces, edge pieces, and end caps. Each of the embodiments of the present invention comprises a unitary structure which may be molded from a plastics material using a variety of molding techniques.
The use of product cushioning devices for shock sensitive products has been known for many years. Typically, cushioning for shock sensitive devices comprises a number of different approaches, each of which may have its own particular advantages and/or disadvantages.
For example, it has been known for many years to wrap shock sensitive or delicate devices or merchandise in tissue paper, and to cushion the products with loosely balled tissue paper. Another use of paper has been shredded paper, or excelsior. A more elegant approach has been to use bubble-pack, which comprises a sheet material having a plurality of contained bubbles of air formed therein. Another approach which has been used for many years has been the use of a plurality of discrete molded foamed polystyrene pellets, sometimes referred to as xe2x80x9cpeanutsxe2x80x9d in the industry, to fill around a product in a container.
As the requirement for better packaging and cushioning became more demanding, for example with the introduction to the market of complicated and expensive electronics devices such as computer monitors, and more particularly notebook computers, printed circuit boards, and the like, the requirement arose for more sophisticated and better shock absorbing cushioning devices. Standards were developed for acceptance of cushioning devices, including drop tests and the like, to determine if such devices would protect the shock sensitive product from shock acceleration greater than the product""s fragility levelxe2x80x94typically, from 20 g""s to 100 g""s.
This has given rise to the use of such products as honeycomb cardboard, and particularly foamed polystyrene, foamed polyurethane, foamed polypropylene, or foamed polyethylene. Flexible foam devices are well known for use as corner pieces or edge pieces. Likewise, foamed polystyrene productsxe2x80x94which are more rigidxe2x80x94are also well known for use as corner pieces or end caps; and very often, they are product specific in that they are particularly molded having a specific configuration for use with a particular product.
In general, however, flexible foam cushioning devices, and foamed polystyrene cushioning devices, are not recyclable. There are several reasons for that condition: The first is that flexible foam cushioning devices, and polystyrene cushioning devices, tend to be quite bulky, and are usually discarded with the packaging container in which the product has been shipped. There are very few specific recycling depots that are set up for either flexible foam or especially polystyrene cushioning devices; and, in any event, foamed polystyrene and foamed polyurethane cannot generally be recycled. Its re-usability may be provided for, particularly as general corner pieces, if they remain intact, or as product specific end caps; but, unless such foamed polystyrene cushioning devices are being used in a closed shipping system, they will not be recovered for re-use. Moreover, foamed polystyrene cushioning devices tend to be very frangible, and do not maintain their integrity very well once they have been used and removed from the packaging container in which they are shipped.
More elegant cushioning devices have more recently entered the market, comprising different types of blow-molded or other plastics shell products, most of which are closed structures which are filled with air or other gas. Some such structures are inflatable, some are closed, and some may be open to the atmosphere but are formed of a relatively rigid material. All such products are generally formed from high density polyethylene, which may be recycled because it is easily chopped up and made into further products, or such products may be re-usable if they are employed in a closed delivery and recovery system. Low density polyethylene may also be found in products such as those described immediately above, although its use is quite limited at the present time.
As will be discussed in greater detail hereafter, the present invention also provides a recyclable and re-usable product cushioning device which has a unitary construction and is formed of a plastics material. As will be noted, the present invention provides such a product cushioning device as a tray or cover, a clamshell, an end cap, a corner piece, or an end piece. However, the present invention does not present a closed structure, such as a number of prior art devices which are discussed hereafter; rather, the present invention provides a product cushioning device which is such that it may be stackable. This feature means that product cushioning devices in keeping with the present invention may be stored in much smaller storage volumes than previously may have been required at the factory or shipping warehouse where the products in association with which the product cushioning devices of the present invention will be used. Moreover, when the products have been delivered to the end user, the product cushioning devices may again be stacked for re-usability, or even roughly cut or chopped up for recycling of the material.
All embodiments of the present invention, as described in greater detail hereafter, provide cushioning and shock force absorption and/or transmission, and thus shock absorbing protection, for whatever product they are being used with, in at least two of three mutually perpendicular axes for which shock absorption protection is requiredxe2x80x94vertical, front-to-back, and side-to-side. In most embodiments of the present invention, apart from edge pieces, shock absorbing protection for a product is provided in all three mutually perpendicular directions.
U.S. Pat. No. 2,874,826 issued to MATTHEWS et al. is directed to a shock and vibration isolation device which, however, is not intended for being incorporated in a rectilinear container. Rather, this device is a resilient and inflatable jacket comprising a plurality of chambers, made of a rubberized fabric which is adapted to hold a gas under pressure, and which will be wrapped around a shock sensitive device such as a guided missile so as to provide a shock and vibration isolation container therefor.
GOBAN U.S. Pat. No. 3,294,223 teaches a molded plastic corner piece having the configuration of a triangular polyhedron which is either rounded or flattened at its apex. The purpose of the corner support is to entrap air between the molded plastic corner piece and the corner of the carton into which it is placed.
U.S. Pat. No. 4,905,835 issued to PIVERT et al. teaches inflatable cushion packaging wherein a plurality of chambers are inflated so as to provide cushioning which will absorb shock and thereby protect a shock sensitive product located in the centre of the container. The amount to which the balloon-like chambers may be inflated, and therefore their hardness, may be controlled.
FOOS et al. U.S. Pat. No. 5,226,543 teaches a packaging structure which includes both a platform portion and a sidewall portion, wherein the sidewall portion forms an enclosure around the platform portion. Essentially, this product is an end cap or platform. The sidewall has both inner and outer walls which are joined by a bridge section, and the inboard wall is relatively shorter than the outboard wall such that the platform portion holds the fragile article at a specific distance above the lower edge of the outboard wall. Shock absorbing formationsxe2x80x94typically, notchesxe2x80x94are formed in the bridge portion of the sidewall. These notches have a degree of elasticity such that, when the packaging structure is loaded and then unloaded, or shocked and then unloaded, the notch will return to its original shape and can absorb multiple loads without deteriorating. However, in order for the elasticity to exist, a material with a high degree of stiffness must be usedxe2x80x94typically, that material is high density polyethylene. The patent requires that the inboard wall is shorter than the outboard wall.
Another patent issued to Foos et al. is U.S. Pat. No. 5,385,232. This patent also teaches a sidewall structure which forms an enclosure around a platform portion. However, the teachings of this patent also address the issue of light shock loads that may not deform or compress the shock load formationsxe2x80x94the notches that are discussed in the previous Foos et al. patent. Here, the concept of openings which provide for collapsibility and allow for the release of compressed air beneath the package when the package is subject to shock loading, is introduced. These collapsible openings may be located in the platform at various locations, and may have a variety of shapes. Still, like the other Foos et al. patent, the teaching is directed to the use of inboard and outboard walls as well as the use of the shock formations (the notches) that have an elastic characteristic.
MOREN et al. U.S. Pat. No. 5,515,976 teaches a structure which has side flanges that are adapted to contact all sides of an end portion of a fragile article, and is thus configured as an end cap. There are a number of protrusions disposed throughout the sidewalls to support the article. There is also a notch provided in the side wall as a means to absorb shock loads. The end cap of this patent is also provided with at least one crush button for absorbing shocks applied along the longitudinal length of the fragile article.
Two related patents issued to DICKIE et al., U.S. Pat. No. 5,626,229 and U.S. Pat. No. 5,628,402 each are directed to a gas-containing product supporting structure which takes the form of a plastic bladder shaped on one side to provide a cavity having internal dimensions which match the external dimensions of the product to be protected, and shaped on its other side to have external dimensions which match the internal dimensions of the shipping container into which it is placed. The product is semi-rigid and self-supporting, monolithic, and gas-containing and may take the form of a corner piece or an end piece or tray for the product to be protected. The semi-rigid and self-supporting gas-containing bladder will retain its shape irrespective of whether it is sealed or open to the ambient surroundings; and will generally comprise a plurality of chambers in the interior of the product supporting structure with gas communication between the chambers so that the gas that is within the structure may flow from one chamber to another during shock loading circumstances of operation.
AZELTON et al. U.S. Pat. No. 5,799,796 teaches a unitary spring system end cap packaging unit. Here, the structure includes an inner wall, an outer wall, and a spring system disposed between them. The spring system includes at least one flexible harmonic bellows which forms a flexible ridge that has an arcuate shape along the length of the sidewall structure. A cushioning space exists between the edge of the inner sidewall and the edge of the outer sidewall. Dimples may be provided on the inner surfaces of the sidewall to allow a friction fit of the end cap to the product over which it will be placed. The arcuate harmonic bellows form flexible ridges that are elastic in nature; and each bellows of the spring system operates independently when a shock load is applied.
A co-pending U.S. patent application in the name of the inventor herein, Ser. No. 09/286,843, filed Apr. 6, 1999, teaches a cushioning device which has a molded post as an integral part thereof. The post is designed to extend into an intersecting corner between two perpendicular packaging container sides, or into the corner formed by three mutually perpendicular packaging container sides. A product supporting surface is spaced away from a related packaging container side by a container contacting flange and a curved ridge. In a shock loading situation, the curved ridge will at least temporarily be further curved away from the post, and the product supporting surface will at least temporarily move closer to it""s related packaging container side.
In its broadest sense, and as a common feature of any of the embodiments of the present inventionxe2x80x94corner piece, edge piece, or end capxe2x80x94the present invention provides a product cushioning device which, in all events, is intended for supporting a shock sensitive product in an outer packaging container. In its broadest sense, the present invention is applicable for use in any container which has at least parallel and planar top and bottom surfaces and at least three planar side surfaces, each of which is perpendicular to the planar top and bottom surfaces. As will be discussed hereafter, there are several embodiments of the present invention, which may be configured as an end cap, a corner piece, a tray or cover, an end piece, an edge supporting piece, or in the form of a clamshell.
Any unitary product cushioning structure in keeping with the present invention is adapted to provide shock absorption protection for a shock sensitive product during shock loading conditions. Those shock loading conditions may be in any one, two, or three of three mutually perpendicular directionsxe2x80x94usually considered to be defined by X, Y, and Z axes. The X-axis is considered to be a side-to-side axis with respect to the cushioning structure, or indeed with respect to the product. The Y-axis is a front-to-back axis; and the Z-axis is a vertical axis. However, those axes, and their orientation with respect to front, back, side, or verticality, are purely arbitrary. Obviously, a product, when packaged, can be loaded, stacked, or dropped, in any orientation. Thus, it will be recognized in the following discussion, and in the appended claims, that discussion of specific axes is, indeed, arbitrary. Indeed, for the most partxe2x80x94at least in the appended claimsxe2x80x94there is no particular reference or relevance to discussions of orientation, except as a matter of convenience.
In any event, and in its broadest sense, the unitary product cushioning device of the present invention is formed of a moldable resilient plastics material:
At least one outer container contacting wall is found in any unitary product cushioning structure in keeping with the present invention, and it provides contact with an outer packaging container in at least a first one of the three mutually perpendicular directions to be considered. There is also a flexible shock absorbing spring transition section which is formed inwardly of the at least one outer container contacting wall.
The unitary product cushioning structure also includes a product supporting region which has at least one outer product supporting region defining wall, at least one inner product contacting wall, at least one upper ridge between the outer product supporting region defining wall and the inner product contacting wall, and a product supporting platform extending inwardly from the inner product contacting wall.
The inner product contacting wall is adapted to provide shock absorption support for a product during shock loading conditions in at least one of the three mutually perpendicular directions. Moreover, the product supporting platform is adapted to provide shock absorption support for a product during shock loading conditions in a second direction, which second direction is perpendicular to at least the first one of the three mutually perpendicular directions, as noted immediately above.
The configuration of the flexible shock absorbing spring transition section is such that it is curved. The direction of the curve is outwardly and away from the product supporting region defining wall which is adjacent each respective flexible shock absorbing spring transition section.
As described above, where the unitary product cushioning structure of the present invention comprises a single outer container contacting wall, and a single outer product supporting region defining wall, together with a single inner product contacting wall and a single ridge formed between them, the unitary product cushioning structure is configured as an edge supporting piece.
A fairly typical configuration of the unitary product cushioning structure of the present invention is as a corner piece. When thus configured, there are two outer containing contacting walls arranged perpendicular to each other, and the two outer container contacting walls are adapted to contact two walls of an outer packaging container which are perpendicular to one another. Thus, the cushioning structure will provide shock absorption protection for a shock sensitive product during shock loading conditions in three mutually perpendicular directions.
Another embodiment of unitary product cushioning structure of the present invention which will provide shock absorption protection for a shock sensitive product during shock loading conditions, in three mutually perpendicular directions, is that which can be considered to be an end cap, a tray or cover; or, alternatively, either half of a clamshell. In such configuration, there are four outer container contacting walls arranged in two opposed pairs thereof, so that the opposed pairs of outer container contacting walls are substantially parallel to one another. The two pairs of outer container contacting walls are adapted to contact four walls of an outer packaging container arranged in the form of a rectangle.
Yet another configuration is that of an end cap, having three outer container contacting walls arranged with one opposed pair of those walls being substantially parallel to one another, and with the third outer container contacting wall being disposed between the opposed pair of walls, and perpendicular thereto. The configuration is such that the three outer container contacting walls are adapted to contact the three walls of an outer packaging container, where two of the three walls of the outer packaging container are substantially parallel to one another and the third wall is disposed between the first two walls and is perpendicular thereto. Once again, this structure provides shock absorption protection for a shock sensitive product during shock loading conditions, in three mutually perpendicular directions.
In some embodiments of the present invention, the outer container contacting wall or walls may be downwardly directed; while, in other embodiments of the present invention, the outer container contacting wall or walls are upwardly directed.
In a particular embodiment of the present invention, where the outer container contacting wall or walls are downwardly directed, such a wall or walls has a bottom edge which provides an outer packaging container contacting surface for the cushioning structure to contact a surface of an outer packaging container in a direction aligned with the at least one outer container contacting wall. Such contact is perpendicular to the at least first one of the three mutually perpendicular directions in which contact is made by the at least one outer container contacting wall.
In another embodiment of the invention, where the outer container contacting wall or walls are upwardly directed, an outer packaging container contacting surface is provided for the cushioning structure to contact a surface of an outer packaging container in a direction aligned with the at least one container contacting wall by at least a portion of the outer surface of the flexible shock absorbing spring transition section.
Indeed, as a general embodiment, but not exclusively as noted above, the outer packaging container contacting surface may be provided so as to contact a surface of an outer packaging container in a direction perpendicular to the at least first one of the three mutually perpendicular directions by which the at least one outer container contacting wall has contacted the outer container, by at least a portion of the outer surface of the flexible shock absorbing spring transition section.
A clamshell unitary product cushioning structure in keeping with the present invention may be provided by having two portions which each have two opposed pairs of outer container contacting walls, each associated with the respective at least one flexible shock absorbing spring transition section, and each portion having a product supporting region. In this embodiment, the two portions of the cushioning structure are bound together by a living hinge formed therebetween.
Some embodiments of the present invention might comprise at least two flexible shock absorbing spring transition sections between the at least one outer container contacting wall and the at least one outer product supporting region defining wall. In this case, the at least one outer container contacting wall is discontinuous between each of the at least two flexible shock absorbing spring transition sections.
In other embodiments of the present invention, there may be at least one flexible shock absorbing spring transition section formed in at least two portions, each separated one from the other by a stiffening rib extending between the respective outer container contacting wall and the respective outer product supporting region defining wall.
In any corner piece embodiment of the present invention, a further embodiment may provide that a portion of each of the outer product supporting region defining walls, a portion of each of the inner product contacting walls, and a portion of each of the upper ridges may be chamfered, in the region where the upper regions intersect to define a corner of the product supporting region of the unitary product cushioning structure. Where the chamfered region is located, a web is formed between the respective outer product supporting region defining walls and the inner product contacting walls.
An end piece configuration of the present invention may also have two chamfered corners, where the three outer product supporting region defining walls, the inner product contacting walls, and the three upper ridges, define two respective corners of the end piece configuration. Here, once again, a portion of each of the outer product supporting region defining walls, a portion of the inner product contacting walls, and a portion of the upper ridges, in each region where the respective pairs of upper ridges intersect, is chamfered, and a web is formed between the respective outer product supporting region defining walls and inner product contacting walls.
Still further, a rectangular configuration of the unitary product cushioning structure of the present invention, such as an end cap or tray, for example, may have a portion of each of the outer product supporting region defining walls, of each of the inner product contacting walls, and each of the upper ridges, in each region where the respective pairs of upper ridges intersect, to be chamfered. Once again, a web is formed in each of the chamfered regions between the respective outer product supporting region defining walls and the inner product contacting walls.
Typically, the length of the inner product contacting wall is in the range of 10% to 80% of the length of the outer product supporting region defining wall. More typically, the length of the inner product contacting wall is generally less than 60% of the length of the outer product supporting region defining wall.
Moreover, the inner product contacting wall may have a convoluted configuration, with a plurality of ridges which extend between the product supporting platform and the upper ridge. This is to accommodate a variety of otherwise more or less similar products, as discussed hereafter.
In any configuration of the present invention, the product supporting platform and the inner product contacting walls may be configured to receive a productxe2x80x94or a portion of a productxe2x80x94which has a predetermined configuration.
In general, the unitary product cushioning structures of the present invention are stackable. This is achieved by molding the cushioning structures in such a manner that each outer container contacting wall, each outer product supporting region defining wall, and each inner product contacting wall, is sloped.
In general, the unitary product cushioning structures of the present invention are thermoformed from sheet plastics material. The compression strength of the molded unitary structure, and thereby its ability to withstand shock forces, will vary as a function of the thickness of the thermoformable sheet plastics material from which the molded unitary product cushioning structure has been thermoformed.
Another manner by which the ability of the unitary product cushioning structure of the present invention may be configured to withstand shock forces is by varying the width and depth of each flexible shock absorbing spring transition section formed in the molded unitary product cushioning structure.
Still further, the outer product supporting region defining wall may be formed in a stepped configuration, so as to have a series of discrete steps.